A system and a method for on-site drug detection and quantification based on the Spectral Fluorescence Signatures (SFS) technology are disclosed in WO2005111586. The system of this invention consists of an ultraviolet-visible light source, a condenser/filter assembly with filter drive, an excitation monochromator with diffraction grating drive, a reference photo-detector, a cell assembly for liquid, solid and powder samples, an absorption photo-detector, an emission monochromator with diffraction grating drive, and an emission photo-detector. A microcontroller unit is provided for device controlling, data processing, and communication with an external computer via different link types. The detection and quantification of illicit drugs in the analyzed sample are provided by measuring simultaneously the emission spectra of fluorescence at every step of excitation wavelength in selected and fixed excitation, emission and absorption spectral windows in a way to cover specific excitation, emission fluorescence and absorption spectral ranges of all major drugs, adulterants and diluents; and processing the united result in a computer system based on combination of preliminary prepared spectral library and specialized software consisting of identification, interaction verification and automatic calibration modules.
A system and a method of analysis of street samples disclosed in WO2005111586 are limited in detection by the concentration of the substances of interest, in particular Cocaine, at that the specific patterns in SFS structure caused by said substances are not recognized by the expert system due to too low their concentration and interfering influence of adulterants and diluents. Additionally to that the cited invention does not provide reliable means to differentiate between Cocaine hydrochloride and Cocaine base due to the same shapes of SFS caused by both forms of cocaine in water.
The need for a technical solution, which increases the selectivity of on-site analysis related to Cocaine detection in a mixture with cutting agents (adulterants and diluents) and allows differentiation between Cocaine hydrochloride and Cocaine base, is mandated by the legal requirements in illicit drug distribution prevention. The current sentencing structure for Cocaine offenses (United States Sentencing Commission. Guidelines Manual. 2004) is the result of the Anti-Drug Abuse Act of 1986. It established mandatory minimum penalties for persons convicted of trafficking in a variety of controlled substances. The 1986 Act pegged the mandatory minimums to specific quantities of drugs distributed. The quantities triggering the Act's mandatory minimum penalties are differed for various drugs and in some cases for different forms of the same drug. Cocaine base, commonly referred to as crack Cocaine, has been treated differently than Cocaine hydrochloride, commonly referred to as powder Cocaine. The Act established what has come to be known as a 100-to-1 quantity ratio between the two forms of Cocaine. It takes one hundred times as much of powder Cocaine to trigger the same mandatory penalties as for a given amount of crack. Congress also distinguished crack Cocaine from both powder Cocaine and other controlled substances in the Anti-Drug Abuse Act of 1988 by creating a mandatory minimum penalty for simple possession of crack Cocaine. This is the only federal mandatory minimum for a first offense of simple possession of a controlled substance. Under this law, possession of more than five grams of crack Cocaine is punishable by a minimum of five years in prison. Simple possession of any quantity of any other substance—including powder Cocaine—by first-time offenders is a misdemeanor offense punishable by no more than one year in prison.
The cited documents illustrate necessity to detect and differentiate Cocaine hydrochloride and Cocaine base and to provide reliable and selective detection of two forms of Cocaine to fight effectively against this illegal drugs trafficking and abuse.